Polarization device for cameras having a linearly polarizing foil



July 19, 1938. M. BURCKHARDT POLARIZATION DEVICE FOR CAMERAS HAVING A LINEARLY POLARIZING FOIL Filed April 12, 1957 1% venl'ar in its plane until its Patentedv July 19, 1938 PATENT OFFICE POIABIZATION DEVICE FOR CAMERAS HAVING A LINEABLY POLABIZING FOIL Max Burckhardt, Jena, Germany, assignmto the firm Carl Zeiss, Jena, Germany Application April 12,

In Germany 1 Claim.

I have filed an application in Germany April 25, 1936.

The invention concerns a polarization device which'is provided with a linearly polarizing foil, for instance of herapathite, and can be used with cameras having a finder.

When the object to be photographed by means of a camera of the said kind is being sought, the foil is to be given sucha position as to influence the rayswhich image the object in the eye, subsequently whereto the foil is to be rotated direction of oscillation provides the most favourable efiect of the foil on the image presented to the eye, and, finally, the foil is to be so placed on the object side of the objective of the camera that the direction of oscillation of the foil coincides with the direction obtained in finding the object.

According to the invention, the foil is held by a carrier which is movably so disposed on the camera, or on a base easily detachable from the camera, that it can assume two positions for use in which the foil is coordinated to'the camera objective and to the finder, respectively, in such a manner that its direction of oscillation is the same in both the said positions,,the mount of the foil being disposed on the said carrier in such a way as to be rotatable about an axis at right angles to the foil, so as to adjust the direction of oscillation of the foil.

The carrier can be mounted on the camera for instance in such a manner as to be rotatable about an axis which is parallel to the axis of the camera objective and so disposed that conveying the carrier from the one position for use to the other can be effected by rotating this carrier through an angle of 180. n

In the accompanying drawing, which illustrates a constructional example of a device according to the invention, Figure 1 is a front and Figure 2 a side view of this example, some of the parts in Figure 2 being shown in section.

In Figures 1 and 2, l designates the housing of a camera which has an objective 2 for the finder v and an objective 3 for photographic purposes The axis X-X of the finder objective 2 is parallel to and above the axis YY of the photographic objective 3. On the, housing I is mounted an arm 4 rotatableabou'r an axis ZZ which lies in the plane of, and is parallel to and equidistant from, the two objective axes X-X and Y'-Y. On the arm 4, a body 5 is mounted for rotation about an axis M--M which is parallel to the axis of rotation ZZ and has a distance from the axis of rotation ZZ eqral to the distance of the two objective axes' X-X and Y-'-Y from 1937, Serial No. 136,363

April 25, 1936 (c1. sis-64) the axis ZZ. The body 5 is the mount of a herapathite foil 8 cemented between two cover glasses 6 and I and at right angles to the axis of rotation M-M. By rotation about the axis ZZ, through an angle of 180", the arm 4 can be 5 given two positions for use. In the position for use represented in the drawing, the axis M-M coincides with the axis X-X of thefinder objective 2. In the other position for use, the axis M-M coincides with the axisY-Y of the photo- 10 graphic objective 3. In the said two positions, the arm 4 is held by an elastic pin 9 extending respectively into an aperture l8 and an aperture Using the device is very-simple: When the arm 15 4 is in that position for use in which the foil 8 is coordinated to the finder objective 2, the mount 5 of the foil 8 is to be rotated relatively to the arm 4 about the axis M- -M until the person viewing through the finder perceives that the foil 20 8 produces the most favourable effect upon the image presented to the eye. Subsequently thereto, by rotation. relative to the camera housing I through 180- about the axis ZZ, the arm 4 is made to assume its other position for use, in which the foil 8 is coordinated to the photographic objective 3. The previously adjusted direction of oscillation of the foil 8- being maintained, the effect of the foil 8 isas favourable whena photograph is taken asit had been in finding the object.

Instead of the finder camera shown in the drawing, any other known finder (for instance a telescopic finder, a brilliant finder or a diopter) can be attached to the camera housing, regardless of what is the position of the front element of the finder, it being easily possible in any case to provide a polarization device according to the invention. 1

I claim:

In a camera having a finder the viewing axis of which is parallel to the axis of the camera objective, an'arm, a transparent linearly polarizing foil mounted on said arm for rotation about an axis at right angles to said 1011, said arm being mounted on the camera for rotation about an axis parallel to first said axis of rotation and to the axis of the camera objective, the axis of rotation of said arm lying in the plane containing the axis of the camera objective and the viewing axis of the finder and being equidistant from these two axes, the length of said arm being such that the polarizing foil may overlie the camera objective or the finder.

MAX BURCKHARDT. 

